This application claims, under 35 USC 119, priority of Japanese Application No. 2002-015197 filed Jan. 24, 2002.
1. Field of the Invention
The present invention relates to a pneumatic rotating tool with an air motor incorporated therein.
2. Description of the Prior Art
Pneumatic rotating tools such as ratchets and drills have heretofore been known. In pneumatic rotating tools, which incorporate an air motor, air is introduced into the air motor to rotate the motor, thereby rotating various tools, including ratchets.
A pneumatic rotating tool is provided with a regulator for adjusting the amount of air to be introduced into the air motor, thereby changing the rotational speed of the air motor. Generally, the regulator is of the type in which the cross-sectional area of an air passage formed on the air inlet side of the air motor is adjusted. Such regulators are classified into those separate from the pneumatic rotating tool and those integral therewith. In the separate type, the regulator cannot be operated with the hand which holds the pneumatic rotating tool and thus with one hand it is impossible to both hold the pneumatic rotating tool and operate the regulator.
Also, in the integral type, it is necessary that a lever for a valve, which adjusts the amount of air to be introduced, be operated with a hand different from the hand which holds the pneumatic rotating tool. Accordingly, it is impossible, with a single hand, to both hold the pneumatic rotating tool and operate the regulator. Thus, change of the rotational speed of the air motor in the conventional pneumatic rotating tool requires that the regulator be operated with a hand different from the tool holding hand, so that the working efficiency is poor.
The present invention has been accomplished in view of the above drawbacks of the prior art and it is an object of the invention to provide a pneumatic rotating tool permitting a finger of the hand which holds the pneumatic rotating tool to adjust the amount of air discharged, thereby changing the rotational speed of the air motor incorporated in the tool.
In one aspect of the present invention there is provided a pneumatic rotating tool having a cylindrical housing, an air motor fixed within the cylindrical housing and having plural exhaust holes, and a communication space formed between an inner wall of the housing and an outer wall of the air motor for providing communication between the exhaust holes and the exterior of the cylindrical housing. A cylindrical regulator is rotatably mounted about a central axis of the cylindrical housing. Retaining means is provided on the inner wall of the housing, the cylindrical regulator being provided with a cooperating retaining means which engages the retaining means of the housing so as to limit rotation of the regulator, relative to the housing, to a predetermined rotational range, the cylindrical regulator being further provided with opening/closing means for opening and closing the exhaust holes formed in the air motor in accordance with the rotational position of the regulator relative to the housing.
In another aspect of the present invention there is provided a pneumatic rotating tool having a cylindrical housing, an air motor fixed within the cylindrical housing and formed with plural exhaust holes, and a communication space formed between an inner wall of the housing and an outer wall of the air motor for providing communication between the exhaust holes and the exterior. A cylindrical regulator is rotatably mounted on the cylindrical housing and has retaining means provided on its inner wall which engages the retaining means of the housing so as to limit rotation of the cylindrical regulator relative to the housing to within a predetermined range, the cylindrical regulator being formed with a stepped inner wall to provide inner surface wall portions radially spaced at different distances from the exhaust holes so that the amount of air discharged from the exhaust holes is dependent on the rotational position of the regulator relative to the housing.